Nicotine Exposure Via Electronic Cigarettes Significantly Impedes Biomechanical Healing Properties of Tendon Healing in a Rat Model.

PURPOSE: To evaluate the biomechanical and histologic effects on Achilles tendon repair of inhaled combusted tobacco versus nicotine exposure via electronic cigarette versus a control group in a small-animal model (Sprague-Dawley rat). METHODS: Fifty-four Sprague-Dawley rats were randomized into 3 groups: combusted tobacco, e-cigarettes, or control. Experimental rats were exposed to research cigarettes or e-cigarette vapor in a smoking chamber for 4 weeks. Surgical transection and repair of the Achilles tendon were then completed, followed by 2 additional weeks of exposure. Achilles tendons were harvested, and biomechanical tensile testing was performed. Histologic evaluation was completed, including hematoxylin-eosin staining, trichrome staining, and immunohistochemistry analysis for type I and type III collagen. RESULTS: The control group showed the highest mean tensile load to failure, at 41.0 ± 10.4 N (range, 18.3-55.1 N); the cigarette cohort had the second highest mean, at 37.3 ± 11.1 N (range, 14.0-54.7 N); and finally, the vaping group had the lowest mean, at 32.3 ± 8.4 N (range, 17.8-45.1 N). One-way analysis of variance showed a significant difference in load to failure when comparing the control group with the e-cigarette group (P = .026). No statistical difference was detected between the control group and cigarette group (P = .35) or between the e-cigarette group and cigarette group (P = .23). Stiffness and qualitative histologic analysis showed no difference among groups. CONCLUSIONS: This investigation shows that in a rat model, nicotine exposure via e-cigarette significantly impedes the biomechanical healing properties of Achilles tendon surgical repair. CLINICAL RELEVANCE: The results indicate that although e-cigarettes are often used as a perceived "safer" alternative to smoking, their use may have a detrimental effect on tendon load to failure.

Preoperative Opioid Use Is Associated With Persistent Use, Readmission and Postoperative Complications After Arthroscopic Knee Surgery.

PURPOSE: To evaluate factors associated with prolonged opioid use after arthroscopic knee surgery and to identify associations between preoperative usage and postoperative complications. METHODS: The MarketScan commercial database was searched to identify patients who underwent arthroscopic knee surgery from 2005 to 2014 (based on Current Procedure Terminology code). Preoperative comorbidities including Diagnostic and Statistical Manual of Mental Disorders mental health disorders, chronic pain, chronic regional pain syndrome, obesity, tobacco use, non-narcotic medications and diabetes were queried and documented. Patients who filled opioid prescriptions 1 to 3 months before surgery were identified. Patients who filled opioid prescriptions after surgery were identified. Adjusted odds ratios and 95% confidence intervals were calculated using multivariable logistic regression analysis to determine factors associated with prolonged postoperative opioid use. RESULTS: In total, 1,012,486 patients who underwent arthroscopic knee surgery were identified, and we determined which of these patients were on preoperative opioids. Preoperative opioid usage was associated with a statistically significant increased risk of usage out to 1 year. There was a statistically significant association between postoperative usage and preoperative variables (mental health diagnosis, smokers, chronic pain, chronic regional pain syndrome, and use of non-narcotic medications). There was a statistically significant association between preoperative opioid use and 90-day readmission and postoperative complications. CONCLUSION: In this study, we found that patients taking opioids 1 to 3 months before arthroscopic knee surgery have increased risk of postoperative use. Additionally, chronic opioid use, chronic pain, or use of non-narcotic medications has the highest risk of postoperative opioid use. Finally, preoperative use was associated with an increased risk of 90-day readmission. EVIDENCE: Prognostic Level IV Evidence.

Outcomes of Clubfoot Treated With Casting in Ghana.

OBJECTIVE: Idiopathic clubfoot deformity is a condition in pediatric orthopedics with a prevalence of 1 in 1000. This study reports the outcomes of clubfoot treatment in Ghana. METHODS: The study was Institutional Review Board (IRB) approved. Patients with clubfoot were treated by the Ponseti method including weekly casting, Achilles tendon lengthening (TAL), and prolonged bracing. Data points collected included: extent of clubfoot, age, relapse, tenotomy prevalence, and number of casts. RESULTS: Out of 1,634 patients, 72.4% were less than a year of age at the time of the first cast, 82.6% had more than eight casts prior to bracing, and 74.0% had a percutaneous Achilles tenotomy prior to the final cast placement. Only 1.2% of patients suffered a relapse. CONCLUSION:  In Ghana, delays in seeking in treatment are common. Optimal results for the Ponseti treatment occur in children who present prior to the age of one. In the current study, 27.6% of children delayed treatment until after one. We recommend a community advocacy program to educate leaders and medical personnel about the Ponseti method. Despite a delay of treatment in 25% of the patients, there was only a 1.2% relapse rate. We recommend the Ponseti method in Ghana for children of all ages.

Microstructural and compositional contributions towards the mechanical behavior of aging human bone measured by cyclic and impact reference point indentation.

The assessment of fracture risk often relies primarily on measuring bone mineral density, thereby accounting for only a single pathology: the loss of bone mass. However, bone's ability to resist fracture is a result of its biphasic composition and hierarchical structure that imbue it with high strength and toughness. Reference point indentation (RPI) testing is designed to directly probe bone mechanical behavior at the microscale in situ, although it remains unclear which aspects of bone composition and structure influence the results at this scale. Therefore, our goal in this study was to investigate factors that contribute to bone mechanical behavior measured by cyclic reference point indentation, impact reference point indentation, and three-point bending. Twenty-eight female cadavers (ages 57-97) were subjected to cyclic and impact RPI in parallel at the unmodified tibia mid-diaphysis. After RPI, the middiaphyseal tibiae were removed, scanned using micro-CT to obtain cortical porosity (Ct.Po.) and tissue mineral density (TMD), then tested using three-point bending, and lastly assayed for the accumulation of advanced glycation end-products (AGEs). Both the indentation distance increase from cyclic RPI (IDI) and bone material strength index from impact RPI (BMSi) were significantly correlated with TMD (r=-0.390, p=0.006; r=0.430, p=0.002; respectively). Accumulation of AGEs was significantly correlated with IDI (r=0.281, p=0.046), creep indentation distance (CID, r=0.396, p=0.004), and BMSi (r=-0.613, p<0.001). There were no significant relationships between tissue TMD or AGEs accumulation with the quasi-static material properties. Toughness decreased with increasing tissue Ct.Po. (r=-0.621, p<0.001). Other three-point bending measures also correlated with tissue Ct.Po. including the bending modulus (r=-0.50, p<0.001) and ultimate stress (r=-0.56, p<0.001). The effects of Ct.Po. on indentation were less pronounced with IDI (r=0.290, p=0.043) and BMSi (r=-0.299, p=0.037) correlated modestly with tissue Ct.Po. These results suggest that RPI may be sensitive to bone quality changes relating to collagen.

Multiscale Predictors of Femoral Neck In Situ Strength in Aging Women: Contributions of BMD, Cortical Porosity, Reference Point Indentation, and Nonenzymatic Glycation.

The diagnosis of fracture risk relies almost solely on quantifying bone mass, yet bone strength is governed by factors at multiple scales including composition and structure that contribute to fracture resistance. Furthermore, aging and conditions such as diabetes mellitus alter fracture incidence independently of bone mass. Therefore, it is critical to incorporate other factors that contribute to bone strength in order to improve diagnostic specificity of fracture risk. We examined the correlation between femoral neck fracture strength in aging female cadavers and areal bone mineral density, along with other clinically accessible measures of bone quality including whole-bone cortical porosity (Ct.Po), bone material mechanical behavior measured by reference point indentation (RPI), and accumulation of advanced glycation end-products (AGEs). All measurements were found to be significant predictors of femoral neck fracture strength, with areal bone mineral density (aBMD) being the single strongest correlate (aBMD: r = 0.755, p < 0.001; Ct.Po: r = -0.500, p < 0.001; RPI: r = -0.478, p < 0.001; AGEs: r = -0.336, p = 0.016). RPI-derived measurements were not correlated with tissue mineral density or local cortical porosity as confirmed by micro-computed tomography (µCT). Multiple reverse stepwise regression revealed that the inclusion of aBMD and any other factor significantly improve the prediction of bone strength over univariate predictions. Combining bone assays at multiple scales such as aBMD with tibial Ct.Po (r = 0.835; p < 0.001), tibial difference in indentation depth between the first and 20th cycle (IDI) (r = 0.883; p < 0.001), or tibial AGEs (r = 0.822; p < 0.001) significantly improves the prediction of femoral neck strength over any factor alone, suggesting that this personalized approach could greatly enhance bone strength and fracture risk assessment with the potential to guide clinical management strategies for at-risk populations.